Carburetor float valve



July 3, 1956 R. H. HiEGER CARBURETOR FLOAT VALVE Filed July 8. 1950 11.5MM 6 O zNVENToR. obef //ecyer BY a 9 M forneq.

United States Patent O CARBURETR FLGAT VALVE Robert H. Hieger, Detroit,Mich.

Application July S, 1950, Serial No. 172,723

2 Claims. (Cl. IS7- 434) This invention relates to carburetors forinternal combustion engines, and more particularly to a lloat valvemechanism for such carburetors.

Most carburetors as now constructed include a fuel reservoir in whichthe fuel is maintained at a substantially constant level by means of afloat which controls the inflow of fuel to the reservoir from anengine-driven fuel pump.

The float controlled valve which regulates the inllow of fuel to thereservoir is often subject to misalignment between the movable valvemember and the stationary valve member, resulting in leakage of fueltherepast even when the valve is in the closed position, with the resultthat at idle, when the rate of fuel ilow to the engine is low, the fuellevel in the reservoir gradually rises, pro-` ducing an overrich mixtureand loading the engine.

Defective operation of the tloat valve mechanism may result from othercauses, and is diificult to detect, since commercial carburetors are soconstructed that itis impossible, without disassembling the carburetor,to apply a measured amount of fluid pressure or suction to the fuelinlet thereof and note the resulting tlow. Also, if leakage is found orsuspected, it is diicult to remedy by means of ordinary shop tools.

The present invention 'aims to overcome these defec by providing a floatvalve mechanism which is self-align` ing; that is, wherein `the movablevalve member is free to move laterally to align itself with its seat.The mecha# nism is `assembled as a unit which may be tested beforeinstallation to detect leakage. The invention comprises various otherfeatures, all of which .are pointed out in the following description,taken in connection with the appended drawing, in which:

Fig. l is a diagrammatic view of a carburetor and the fuel systemthereof showing, on an enlarged scale,` one form of the presentinvention incorporated therein.

Fig. 2 is an enlarged sectional View of the lloat valve mechanism andits associated parts.

Fig. 3 is a horizontal sectional view taken on `the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2, but showing a modited form of valvemechanism.

Fig. 5 is a similar View showing a further modilied form of theinvention. f

It is to be understood that the invention is not limited 'in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawing, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also it is to be understood that .the phraseology or terminologyemployed herein is for the purpose` of description and not oflimitation.

The carburetor shown in the drawing is of the downdraft type commonlyused with automobile engines, but may be of any known or suitableconstrue-tion. It comprises a body 8 forming an induction passage whichincludes an air inlet lli, a main venturi 12, and a mixture outlet 14designed to be connected to the intake manicounterclockwise direction.

r. ICC

fol-d of an internal combustion engine, not shown. The induction passageis controlled in the usual manner by a manually operated throttle valvelo. Usually an air cleaner, such as is indicated fragmentarily at i8, isconnected to the air inlet. Fuel is supplied to the inductionpassagefrom a reservoir Ztl, which in the example shown is a floatchamber having a float 22 therein, which actuates a valve unit indicatedgenerally at 24 and controlling a fuel inlet 26 leading from a source ofpressure, such as the usual fuel pump, not shown. From the reservoir 20the fuel flows through a passage 28 to the main fuel nozzle 32, whichdischarges at the throat of the main venturi 12.` In the example shown,a second venturi 34 is provided to form a `discharge member for the mainnozzle. A metering oriiice 36 is provided in the passage 2S, as is theusual practice, and an idling fuel passage of any suitable construction,not shown, may lead from the passage 32 to` a point above the fuel levelL and discharge adjacent the engine throttle 16 when the same is inclosed position.` An economizer 38 of known construction is indicatedschematically in the drawing, .and may be of the type disclosed in mycopending application Serial No. 158,537 tiled April 27, 1950, nowPatent No. 2,617,640 dated Nov. ll, 1952. Suitable acceleration pumpmechanism, as well as check valves, vents, and metering ori- `ces may beprovided,` as known in the art.

In the -form of the mechanism shown in Fig. l, the fuel inlet conduit26-connects with the bore 40` of a boss 4l formed on the tloat chambercover 42. The boss is internally threaded tol receive the threadedreduced end 44 of the valve body. The lower end of the valve body isenlarged to form a sleeve 46 which acts as a guide for a movable valvemember 43. The member 48 is of generally triangular crosssection, andisof known construction except as modied for purposes of this invention.As shown, it is machined 'to form notches '50 in its vertical ribs, tothereby reduce the weight of the member and thereby minimize the effectof its impact against its seat, as occurs when the vehicle is subjectedto vibration, and which tends to damage both the valve member and itsseat.

The upper end of the valve member 48 is formed with three prongs` 2which extend upwardly from the body of. the member and then` inwardly toform a cage loosely enclosing an obturating member or valve element inthe Iform of a ball 54 which is designed to cooperate with the lower endof a` bore 56 in the upper portion 44 of the tubular valve body, which`thus forms a seat for the ball. In order to permit the ball to movelaterally within the limits of its cage, and thereby align itself withits seat, it is seated on a washer 58 which is slidable upon the base ofthe cage. The valve member `4dispreferably drilled longitudinally -to`form a bore 'S7 through which a tool may be inserted to strike ball 54and vthereby deform the metal of member `4d to cause the seat to conformclosely to the shape of the ball.

` Thelloat 22 is` carried by a lever "59 which has oneof its endssecured to the float andis pivoted at 60, so that upward movement of thetical, resulting from rise in the fuel level L, will cause the lever torotate in the A tang 62 is struck out of the metal of the lever 59 andcontacts the lower end of member 48, in known manner, so that as thefuel level rises it moves member 48 upwardly and closes the Valve; Asthe ball S'd'comes `intol Contact `with its seat, it` adjusts itself bymoving with washer .53 laterally to thereby align itself with its seat.When the ball is moved away from its seat, vibration and other factorsmay move lthe ball and washer out of alignment, but upon each return ofthe 'ball to its seat the alignment will again be effected. ln the formof the invention shown in Fig. 4, the mov able Valve member 48 is shapedapproximately the same as in Figs. 1-3, but the obturating member orvalve element is in the form of a pin having an enlarged cylindricalhead 64 and having a reduced portion which terminates in afrusto-conical surface 65 designed to cooperate with the lower end ofbore 56 to control the flow of fuel. The pin is laterally slidablerelative to valve member 48, so that it will adjust itself to alignmentwith its seat in the same manner `as described in connection with Figs.143, and the prongs 52 in this case engage the sh-oulder formed by theupper end of portion 64. The pin has a shank 66 which extends into 'bore'57 and. may be struck with la tool to shape the surface 6'5 to itsseat.

In the modification shown in Fig. the structure is generally the same asin Fig. 4 except that the reduced portion of member 64 and the cageformed by prongs 52 are omitted; the shank 66 of the valve member 64being of suiciently smaller diameter than the internal bore 57 toprovide a clearance space shown in the drawing, the member 64 is thusmade free, unless restrained 'by some external means, to move withrespect to member 48, the shank 66 thereof moving within the bore 57. Byvirtue of such a construction, the bore 57 becomes open at both rof itsends should the member 148 move downwardly away from the member 64seated at its seat, thus permitting gasoline to flow through said bore57 in either direction depending upon the relative pressures existingunder such condition at the ends of the internal bore 57. Inconsefquence -thereof any foreign matter that may Itend to accumulatewithin the bore `57 or 'between the top surface of the member 48 and thebottom surface of the head of the valve member 64 `is washed out, thuspreserving the freedom of the movement of the member 64 with respect tothe member 48 when the sealing surface '65 of said member 64 tends toaccommodate itself to the valve seat. I have found that unless suchcirculation of fluid is produced, recesses such as 'bore 57,particularly if closed at the bottom, soon become traps for Iforeignmatter and, upon getting filled with dirt, disorganize operation of thevalve making it less dependable than solid or one-piece valves.

As in cases of other embodiments of the invention, the bore 57 of theconstruction of Fig. 5 may be used for the passage of a tool to strikethe shank 66 in order to peen or burnish the seat for the cone-shapedvalve portion 65.

In any of the forms of the invention disclosed, the valve body 44, 46may be formed of brass or other material which is resistant -to theaction of gasoline and the acids or other impurities contained therein,land the obturating member may be of stainless steel `or othernoncorrodible material which is also resistant -to wear. In order tofurther minimize the inertia effect whereby the obturating member ispounded against the seat by vibration, the obturating member may beformed of a light gasoline-resistant plastic such as cast nylon, whichmay be machined to -fit accurately to its seat.

The valve mechanism 'herein disclosed is particularly resistant tofactors tending to cause leakage, but if there is a question 'whetherfuel is escaping past the obturating member 54 or 65 when the valve isclosed, or if it is desired to test the functioning of the valve undervarious degrees of pressure, it `is only necessary to remove the floatchamber cover from the carburetor and unscrew the valve unit therefrom.A measured force, corresponding to that exerted by the iloat When thelevel L is at its designed maximum, may 'then 'be applied upwardly onvalve member 48, while a measured fluid pressure is applied to the bore56, to determine whether the valve unit passes any fluid when closed.Where leakage is i found, a punch or other tool may be inserted in bore57 to tap the obturating member 54 or 65 and cause the seat to conformto the shape of the obturating member.

Although the invention has been described with reference to theillustrated embodiments thereof, it may be embodied in other formswithin the skill of artisans in this art, and is not limited except bythe terms of the following claims.

I claim:

1. In a carburetor having a fuel reservoir, a fuel inlet to saidreservoir, a valve mechanism controlling said inlet, and a floatAoperatively connected to said valve mechanism for `actuating the samein response to level of fuel in said reservoir; said valve mechanismcomprising a removable valve body, .a passage in said body to provide acontrolled fuel passage therethrough, a valve seat formed `in saidpassage, a movable valve-carrying member having -a through inner passageand at least one through outer passage for passage of fuel througheither of said inner and said outer passages, a valve element carried bysaid movable member and having `a sealing surface cooperating with saidvalve seat to close and to open the same and a pressure surfacecooperating with la surface on said movable member, said surfacesforming when separated, a fuel passage communicating with said innerrecess to permit ow of fue1 between said pressure surfaces.

2. In a carburetor having a fuel reservoir, 'a fuel inlet to saidreservoir, a valve mechanism controlling said inlet, `and a floatoperatively connected to said valve mechanism for actuating the same inresponse to level of fuel in said reservoir; said valve mechanismcomprising a tubular body having a fuel passage therethrough with avalve seat formed therein in one of its portions and being enlarged inits lremaining portion to have a cylindrical recess, e. cylindrical bodyslidably lfitted into said cylindrical recess and having outer recessesto provide fuel passage therethrough and an inner bore open at bothends, a valve element carried by said cylindrical body and comprising acone shaped head adapted to cooperate with said valve .seat to close andto open the same, and a shank loosely fitted into said bore to providefor relative longitudinal and limited transverse movement of said Valveelement with respect to said cylindrical body, said cone head thushaving provided thereon a shoulder bearing on said member fortransmission of valve closing forces but providing` fuel passage whenthe shoulder is separated from said member.

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